Property tycoon Donald Trump has threatened to sue a Miss Universe contestant for accusing him and his partners of rigging Sunday's (03Jun12) Miss Usa pageant.Miss Pennsylvania Sheena Monnin, 27, upset Trump, who owns the beauty show, when she resigned her title and quit the Miss Universe Organisation, but it's what she posted on her Facebook.com page afterwards that has enraged the businessman. Monnin wrote, "Effective immediately I have voluntarily, completely, and utterly removed myself from the Miss Universe Organization. In good conscience I can no longer be affiliated in any way with an organization I consider to be fraudulent, lacking in morals, inconsistent, and in many ways trashy." Calling in to U.S. breakfast show Good Morning America on Wednesday (06Jun12), angry Trump said, "She made a very false charge and she knows it was a false charge. I think that, frankly, she should apologise but we will be bringing a lawsuit against her. "It's absolutely ridiculous. She lost and if you look at her compared to the people who were in the top 15, you would understand why she's not in the top 15. It's a very, very sad situation."